A Russian judge is facing disciplinary action after he was caught on camera napping and playing with his mobile phone during a trial that ended with him sending a man to a penal colony for five years.

Yevgeny Makhno, a judge at Blagoveshchensk City Court in Russia's Far East, can be seen nodding off and then sleeping soundly with his head slumped on his shoulder as a lawyer speaks in the background.

In another video, the dishevelled-looking judge appears to be scrolling through a website or checking messages on his mobile phone.

Vladislav Nikitenko, a rights activist who posted the videos online, said they were passed to him by relatives of the accused, Andrei Naletov, who was convicted of fraud and given a five-year custodial sentence last summer.

Mr Nikitenko has issued a complaint to Russia's Constitutional Court calling for the slumbering judge's decision to be cancelled. "A verdict made on the basis of a hearing in which the judge took no interest in the court investigation and slept during the pleadings cannot be considered lawful," he said.

Blagoveshchensk City Court said it had launched an investigation and the result would be known next week.